1. Field of the Invention
The present invention generally relates to a display, in particular, to a liquid crystal display (LCD).
2. Description of Related Art
Thanks to the advantages of high definition, desirable space utilization efficiency, low power consumption, and no radiation etc., the LCD has gradually become the main stream of the displays. As the prevailing of the LCD, one of the important indexes to be considered by the consumer when purchasing the LCD is high color reproduction. Recently, in order to meet the consumers' requirements, various LCDs adopting the high color reproduction technique have successively appeared on the market.
The LCD is mainly constituted by a liquid crystal display panel and a backlight module for providing a light source for the liquid crystal display panel, in which the liquid crystal display panel includes, for example, an active device array substrate, a color filter, and a liquid crystal layer sandwiched there between. Generally, the light source in the backlight module may adopt a cold-cathode fluorescent lamp (CCFL), a light emitting diode (LED), or other types of light sources. Taking the CCFL as the white light source in the backlight module for example, currently, the color saturation NTSC ratio of the LCD approximately reaches a level from 70% to 75%, in which the color saturation NTSC ratio is used to evaluate the color saturation according to the standard issued by National Television System Committee (NTSC).
FIG. 1A is variation diagram of chromaticity coordinates when the high color reproduction technique of the LCD is developed according to the conventional art. Referring to FIG. 1A, through changing the type of the fluorescent powder in the CCFL, for example, changing the green fluorescent powder with an intensity peak between 540 nm and 550 nm to the green fluorescent powder with an intensity peak between 510 nm and 520 nm, the color saturation of the LCD after the adjustment is improved. However, on the other hand, the color temperature shift of the white point for the LCD occurs after adjustment, such that the color representation of the LCD is distorted.
In order to solve the above problems, as shown in FIG. 1B, it is a variation diagram of chromaticity coordinates when the high color reproduction technique of the LCD is developed according to another conventional art. Through adjusting the ratio of red fluorescent powder, green fluorescent powder, and blue fluorescent powder in the CCFL, the white point color temperature of the LCD after the adjustment is improved, but on the other hand, the color saturation is sacrificed.
To sum up, it has become an important issue in the high color reproduction technique how to improve the color saturation while considering the white point color temperature representation of the LCD.